Java中的 FileStore getUnallocatedSpace() 方法及示例

FileStore类的getUnallocatedSpace()方法用于获取文件存储中未分配的字节数。此方法对于检查可用空间很有用。此方法将可用的未分配空间作为长值返回。
句法：

public abstract long getUnallocatedSpace()
                     throws IOException

参数：此方法不接受任何内容。
返回值：此方法将可用的未分配空间作为长值返回。
异常：如果发生 I/O 错误，此方法将抛出IOException 。
下面的程序说明了 getUnallocatedSpace() 方法：
方案一：

Java

// Java program to demonstrate
// FileStore.getUnallocatedSpace() method
 
import java.io.IOException;
import java.nio.file.FileStore;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
 
public class GFG {
 
    public static void main(String[] args)
    {
        // create the object of Path
        Path path
            = Paths.get(
                "E:\\Tutorials\\file.txt");
 
        // get FileStore object
        try {
 
            FileStore fs
                = Files.getFileStore(path);
 
            // print FileStore name and Total unused size
            System.out.println("FileStore Name: "
                               + fs.name());
            long bytes = fs.getUnallocatedSpace();
            long sizeInGB = bytes / (1024 * 1024 * 1024);
            System.out.println("Free Space : "
                               + sizeInGB + "GB");
        }
        catch (IOException e) {
 
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

输出：

方案二：

Java

// Java program to demonstrate
// FileStore.getUnallocatedSpace() method
 
import java.io.IOException;
import java.nio.file.FileStore;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
 
public class GFG {
 
    public static void main(String[] args)
    {
        // create the object of Path
        Path path
            = Paths.get(
                "C:\\Movies\092;048;01.txt");
 
        // get FileStore object
        try {
 
            FileStore fs
                = Files.getFileStore(path);
 
            // print FileStore name and Total size
            System.out.println("FileStore Name: "
                               + fs.name());
            System.out.println("Free Space in bytes: "
                               + fs.getUnallocatedSpace());
        }
        catch (IOException e) {
 
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

输出：

参考资料：https: Java/nio/file/FileStore.html#getUnallocatedSpace()